The present invention relates to a tube clamp for securing a flexible tubular member for example a hose to a rigid tubular member, and more particularly to an improved structure of tube clamp which can be efficiently and smoothly tightened up with less effort.
FIGS. 1 and 2 show a tube clamp according to the prior art. This structure of tube clamp comprises a transversely grooved binding strap 2 having an opening 4 at its lead end, a screw holder 1 fastened to the opening 4 of the binding strap 2 by its integrated clamping plates 3, and a screw 5 mounted in the screw holder 1 and turned to move the tail end E of the binding strap 2 over its lead end in tightening up the tube clamp. The screw 5 has threads 50 meshed with transverse grooves 24 at the binding strap 2. This structure of tube clamp is not satisfactory in function. One drawback of this structure of tube clamp is that the hinged clamping plates 3 of the screw holder 1 may be forced to disconnect from lead end of the binding strap 2 when the tube clamp is excessively tightened. Another drawback of this structure of tube clamp is that the formation of the transverse grooves 24 at the binding strap 2 weakens the structural strength of the binding strap 2, causing the binding strap 2 to be easily broken. Furthermore, because only about 3.about.4 transverse grooves 24 are maintained in mesh with the threads 50 of the screw 5 and the engagement between the transverse grooves 24 and the threads 50 does not reach the roots 51 of the threads 50, the screw 5 tends to be turned in idle. FIG. 3 shows another structure of tube clamp (U.S. Pat. No. 5,787,555, which was issued to the present inventor). This structure of tube clamp comprises a screw holder 1 having two clamping plates 3, a screw 5, and a binding strap 20. The binding strap 20 has a plurality of transverse slots 201, and an opening 4 at its one end namely the lead end. The screw holder 1 is fastened to the lead end of the binding strap 20 by its clamping plates 3. The lead end of the binding strap 20 comprises two longitudinal bridging elements 22 longitudinally disposed at two opposite sides of the opening 4, four rounded convex portions 21 in four corners of the opening 4, four rounded concave portions 23 respectively disposed between two opposite ends of the bridging elements 22 and the rounded convex portions 21, and four projecting stop portions 220 respectively and outwardly disposed at two opposite ends of the bridging elements 22. When the screw holder 1 is installed, it is stopped between the projecting stop portions 220. Therefore, the screw holder 1 does not slide when the screw 5 is turned to move the tail end E of the binding strap 20 relative to the lead end of the binding strap 20. This structure of tube clamp is functional, however it still has drawbacks. The opening 4 weakens the structural strength of the lead end of the binding strap 20, causing the lead end of the binding strap 20 to be easily deformed. Furthermore, because only about 3.about.4 transverse slots 24 are maintained in mesh with the threads of the screw 5, the screw 5 tends to be turned in idle.